Art of extruding cork for the manufacture of bottle caps and the like



April 5; 1958 A. WEISENBURG 2,830,326

' ART OF EXTRUDING CORK FOR THE MANUFACTURE OF BOTTLE CAPS AND THE LIKE3 Sheets-Sheet 1 Filed June 8, 1953 INVENTOR April 15, 1958 A.WEISENBURG 2,330,326

ART OF EXTRUDING coax FOR THE MANUFACTURE OF BOTTLE CAPS AND THE LIKE 3Sheets-Sheet 2 Filed June 8, 1953 IN VENTOR MAX 1 A TTOKNE Y5- April 15,1958 A. WEISENBURG 2,830,326

ART OF EXTRUDING coRK FOR THE mumc'ruas 0F BOTTLE CAPS AND THE LIKE 3Sheets-Sheet 3 Filed June 8, 1953 wm im III/l/II/IIIIII ATTORNEYS UnitedSW68 a ent 0 ART OF EXTRUDING CORK FOR THE MANUFAC- TURE 0F BOTTLE CAPSAND THE LIKE Andrew Weisenburg, Langhorne, Pa.

Application June 8, 1953, Serial No. 360,023

8 Claims. (CI. 18-55) I This invention relates to a method for themanufacture of articles of granulated cork, particularly rods of corkfrom which bottle caps, seals, gaskets, packing rings and the like maybe cut.

The invention will be described in connection with th production of rodsto be cut into disks for bottle cap seals.

I am aware that this is a relatively old art. The processes and machinesused therefor are slow in production, and produce rods of relativelyshort length, in consequence of which a large number of machines must beemployed for a given production, with consequent high costs in equipmentand in labor, etc. Moreover, generally speaking, the rods produced arenot consistently uniform as todensity, which is an importantconsideration.

The chief objective of this invention is to make it possible to producerods of comparatively great length, and at high speed, whereby it ispossible to obtain large production with relatively few machines, at lowcost in investment and in labor. I accomplish this objective while alsosecuring a rod of improved uniformity as to the desired density.

Briefly stated, the preferred way of practicing the invention consistsin mixing granulated cork with a binder which, when the mixture issubjected to heat and pressure, will unite the particles together;successively forming slugs of the cork and binder mixture, the amount ofmaterial in each slug being substantially the same; then forming the rodby successively forcing slugs through a long extrusion tube (or die ormold) of a construction permitting radial expansion of the mixture atprogressive points or regions within the tube as it passes therethrough;heating the tube substantially throughout its length; and finishing orsizing the discharging end portion of the rod in a finishing or sizingtube where the rod is cooled.

This combination of steps results in a realization of the objective. Toillustrate, by utilizing a long tube a plurality of slugs can besuccessively introduced into and forced therethrough; by providing aplurality of successive regions for progressive radial expansion, therod being formed can be forced through the tube without the de- 55velopment of unduly high frictional resistance or binding of the corkagainst the tube wall, as the cork swells during the heating operation.Thus great speed of rod production is possible While at the same timeundesired densifying of the cork rod being formed, is avoided and therod exits with uniform density of the desired degree. By heating thelong tube substantially throughout its length, it is possible to securethe desired final setting (or polymerization or coagulation) of thebinder, with low temperature, thus avoiding discoloration and charringof the cork. The latter is objectionable because it imparts a taste tothe contents of the bottle. The heating of the long tube substantiallythroughout its length also makes it possible to secure the desireddegree of final setting of the binder with low heat, despite the rapidprogress of 0 the rod through the tube. Likewise, the lubricatingproperties of the binder are thereby more effectivelyrnade availableduring the passage of the rod through the tube,

ice

which again affects friction, speed and densification. By feeding inequal amounts of charge, a uniform rate of feed results and thetemperature relationship set for a given speed, is not disturbed.Likewise the combination of the steps results in a bringing about of astate of equilibrium as hereinafter set forth, so that the finishedproduct thereafter discharges with substantial uniform density.

Another objective of the invention is to facilitate the starting up ofthe rod-forming operation after shut-downs, as will hereinafter morefully appear.

The manner in which the method is carried out and typical examples ofmachines that may be used for the method will be apparent from thefollowing description and drawings, wherein- Figure 1 is an elevationalview partially in section, taken on the line 1-1 of Figure 2illustrating a machine for carrying out the process;

Figure 2 is a plan view taken along the line 2-2 of Figure 1; I

Figure 3 is a view partially in section taken along the line 3-3 ofFigure 1;

Figure 4 is a plan view partially in section illustrating another typeof machine used to practice the method; and

Figures 5 through 10 illustrate the manner in'which slugs are formed andforced through the extrusion tube.

Referring first to Figures 1 and 3, the two banks of extrusion tubes aregenerally designated by the reference characters D and D, the cork andbinder hopper by H, having downwardly extending legs h-l andh-Z, thelegsbeing secured to the frame F. The plungers are designated by thereference characters P and P, the support for the plungers by S, thepiston rod for reciprocating the plunger holder and the plungers by C,and the hydraulic cylinder for actuating the-piston rod by C, thecylinder being secured to the frame F. The slug-forming mechanism isgenerally designated by the reference characters M and M, which isadapted to reciprocate from left to right as viewed in Figure l. The rodbeing extruded is designated by R.

It will be apparent that each tube has a plunger and a cork-feedinghopper leg associated therewith. All of the extrusion tubes areidentical in construction and, therefore, description will be made onlywith reference to tube a shown in Figure 3. a v

The tube d is generally tubular in shape and is comprised of a pluralityof threaded tubes 1, 2, 3, 4 and 5, which are joined together by thecouplings 6, '7, '8 and 9. Tube 5 is the finishing or sizing tube andhas a diameter designed to give a rod of required cross-sectionaldimensions. From an inspection of Figure 3, it will be apparent that theinside diameter of the tube is greater at successive points along theaxis thereof. This is accomplished in the embodiment shown by usingtubes of different diameter. Tube 1 has the smallest diameter, and thesucceeding tubes become progressively larger. Tube 5 has the largestdiameter and is designed to extrude a rod of the required dimensions. IThe arrangement of the tubes as described permits radial expansion ofthe slugs or mass of cork and binder with progression along theextrusion tube. This feature is used in the control of the density ofthe formed rod. The tubes 2, 3 and 4 are equipped with heating coils 1t11 and 12, which extend substantially throughout the length of theportions 2, 3 and 4. A single heating coil can be used. In the preferredembodiment, however, individual coils, individually controlled, areused, so that the amount of heat developed byeach may beindependentlyadjusted. The details of. the control system are not shown because suchsystems are well known to-. those skilled in the art. For example, inits simplest tome-a-ceilnsawbe conneeted to the source of power througha manuallyl operable rheostat.- The 'heat from the coils is used to setthe binder. The setting gradually progresses until about the ti'rne theend of tube 4 is it is desirable te -nave tube 5 or slightly larger"diameter thanftube 4'.

Tube 5 is reterably cooled in any preferred manner as by roviding awaterjacket wi'th inlet and outlet for cir- V to" reeeive' theplunger 203Betwe'irthe 'top' an'd b'ottom plates of the frame are securedside'plates21'and'2'2; be tween which the slugforniing mechanisms M and'M are adapted to reciprocatel The mechanisms M and M are-identicalin=construc tion and refernce will' be made onlywith respect tomechanism M, It is pointed out that these parts are adaptd-toreciprocatein unison by means of conventional mechanism not shown.

The' slug forming mechanism M is generally elongated andextendsbetweenthe plates 14- and 17 (Fi ure 1); while the sides bear onendplates 21 and 22. meehanism'has a pluralityof bores or flasks whichreciprocatebetwe'en an extrusion" tube and acork hopper. For ex'ainple',the flask 23"-(in th'eform of'a' tube) reciprocate's betw'cen-theimouth24'of'tube d and the'mouth 25 of QPprfle'g 26j'wh'ile thefla'sk' 27 reciprocatesbetweehfth'emouth 28 or hopper le -'29 and themouth 24 of tube d5 i In the preferred"embodiment; the axes of the tubesD and D" and' the hoppers H" are arranged in a vertical plane as thisfacilitates the" fla'sk being filled 3 each time with'aii equalamount'of material. .Theplungers P and P"also rrio've'in -a' verticalplane and the slug-forming mechanism M' reciprocates in a horizontalplane.

The binder which I prefer to use is the thermosetting type} for example,gelatin; casein, albumen, urea, phenolic, alkyd or other resinousmaterials. Other binders may be used which will react tocoagulate thegranules of cork together;

The-manner in which a"slugof cork and" binderis' formed and" forcedthrough the extrusion tube will I be described in connection withFigures 1 and .Sthrou'gh 10.

Injth'e' operativeposition? of thernechanism, as seen The are filled"with a 'ma'ss ofcotk and binder. Thus, as

seen in Figure 5, when the flask 27 is I below" the "mouth 28o the hoper-reg, a-mas-s ot co'rkand' binder; which hasdi'opped" down fr'o'mthe' hoppe'r le'g 29, is disposed therein: Thememb'er-Mthen moves totheright'between thep'lates" l'4 and 17, resultin'g'in a slu'g 30 beingposi tionedatfthe mouth 24' orthetube (seeFiguie 6) The plunger'20isthen moved-upwardly tomove the slug into the'tu'be '1. As will be'apparentfrom' Figure 7, theslug 3U is=- compressed asit is rr'iovedinto the" tube 1 by the plunger 26. The plunger 26is then retracted'from the" the'right againwithj the charges in position to be againoperatedupon by the p'lhn'gers; The plungers then move upwardlyand the"second slug-31 is thenforr'ned in the tube beneatlitlfe' slug @0,advancing the slug along 7 the'tiibe The operation is then repeated anda new charge brought inposition, as illustrated in Figure 10.

These"o eratinns continueuntil theentire length of the" Assuming thatthe empty machine is started up, the operation goes on as .2 abovedescribed and thetube Vbe= comes filled. The leading portions of the rodbeing extruded from the tube 5 will be useless until equilibriumconditions are reached within the tube. These equilibrium conditionswill obtain when the tube has been filled once and the lowermost slugportion reaches the top, and when the filledtube has again been filledand the-lowermost slugportion'hasreached the top. From then on; therewill be equilibrium and the rod will discharge with uniform density.

It will, ofcou'rse; be understood that the contents of the hoppers-arekept ina free-fiowingcondition as by stirring, as is well understood inthis art. Thus, there will be no hang upand each flask'will always befilled with an equal amount of cork mixture when the flasks are incharge receiving position.

While the rod is being formed and forced through the extrusion tubes;heat is applied as b'efo're described:- forsubstantiallythroughoutthe'length'of the tube. Hence; in" portion-22. ofthe tub'es sorn'e' expansion will take-place for which reason suchportion of the tubesis somewhat larger-in diamete'r 'thair theportion 1. Similarly portion 3 of the tubeis somewhat larger indiameterthan p'ortion" 2, portion4 of the extrusion tube is greater thanportion 3, and'po'rtion 5is 'soniewhat'greater than portion 4. Thus,asthe rod is being formedand moves through the ex t'rusio'ri' tubesandbecbms hotter and'hotter, rovisien is madefonradialexpansioninsuc'cessive regions,f each of somewhat 'la'rger' diameter, thusallowing for the swell ing whicho'ocur's'during the heating; thusavoiding objectionable' friction resistance which would produce'anundesrr'eddegree ofcor'npacting andenabling the cooling portion"to acta's th'e final sizingmemberand"ensuring that the rod-will discharge withthe particular density" desired and with unifbr'mity 'of such density;A's pre viously pointed out, when the equilibrium conditionswhichdetermine the ultimate density are reached,- fro'tn then on the rodbeing formed will be of substantialunh formity as to density. Byvariation of the amount of expansion permitted or the length of the tubeportions;

or'both, control of the ultimate density obtained is made possible:

While; as indicated; there maybe some variation" in diameter and alsointhe length of the respective portions per minute, of a 1 inch diameterrod, having desirable density cliar'acteristicsl The flasks in suchinstance would be about 6" long and of 0.9375" 1. D. The portionsofthe-extrusion tubes would be of the following dimen-- Tube 1, 0193751.1):, 3-9 long Tube 2, 10000 I. D., .15 long Tllbe 3, 1 .03101; D., 15"long Tube 4, 1.0520 1. D., l 5'long Tube 5, ll0625 I. D., 6-15" long Onefoot per minute is a-relatively quite high rate of extrusion as comparedto present practice, and by my in ven'tion it is possible; to evensubstantially exceed one foot per minute'without impairing of. theresults; To

obtaina given density; if the strokes per minute be increased then thelength of the tubes is correspondingly increased, and vice versa, if thestrokes be decreased then the length of'the'tubesis decreased.

The portion 1' of the'tubenecd only be long enough to ensure'that theslugintroduced therein is sufiiciently compacted to ensure no flowingback of the material. Uually-froni3 to 9 inches of length aresufficient-for the purpose.-

It will be seen that the process :is such that high rates of productioncan be obtained, which means that such production can be obtained withmuch fewer machines than heretofore required for such production.

Rods may be extruded anywhere from to to 30 feet or longer, as desired.

Ordinarily I may operate at a temperature of from about 300 to about 350F., but I prefer to operate at a temperature of about 330 R, which arerelatively low temperatures.

When following the process herein described, I find that I do not haveto change the cork and binder mixture as is frequently required inconventional practice. This enables me to make up relatively largebatches of cork mixture which will last for an appreciable period oftime before being used up.

An alternative type of machine which may be used to practice theinvention is shown in Figure 4. This is a rotary type apparatus havinghoppers H-2 and tubes D4. The plate 33 carrying the flask 34 is adaptedto move relative to the hoppers and tubes. The plate 33 may rotatecontinuously relative to the hoppers and tubes or the motion may bereciprocatory.

With either of the above described types of machines, conventionalmechanism to coordinate the motion of the plungers and slug-formingmechanism is provided. Such mechanism may take a variety of forms. Noparticular mechanism is shown, as such apparatus is well within thepurview of those skilled in the art.

While I have shown two embodiments of apparatus for practicing themethod, it will be apparent that other types of apparatus may be used.

When starting up cork extruding machines after, say;

overnight shutdowns, it is sometimes quite diflicult to dislodge thecork left in the tubes. I have discovered quite surprisingly that if thetemperature be increased for some period of time at shutdown or beforestarting, no particular difiiculty is encountered in starting. To thisend, I raise the temperature and heat for a suflicient length of time sothat the mixture remaining in the tube will be set. Once the mixtureremaining within the tubes is set, it can readily be discharged uponagain starting up the machine. As illustrative, I may raise thetemperature above normal operating temperature about 25 F. for a periodof about 4 or 5 minutes.

While I have described and claimed the invention in relation to rods, itwill be understood that the invention is not specifically limitedthereto. It will also be seen that in certain aspects the invention isbroader than the preferred procedure set forth.

I claim:

1. The method of continuously extruding a mixture of granulated cork andthermosetting binder in the form of a rod comprising the steps of:sequentially forming slugs of the mixture each having the same volumeand the same cross-sectional area; and forming a rod therefrom bypressure moving the slugs one after another into and through at leastthree sequentially serially arranged heated binder-setting rod-formingstages in each of which the rod has a cross-sectional area slightlygreater than it has in the immediately preceding stage.

2. The method of continuously extruding a mixture of granulated cork andthermosetting binder in the form of a rod comprising the steps of:sequentially forming slugs of the mixture each having the same volumeand the same cross-sectional area; forming a rod therefrom by pressuremoving the slugs one after another into and through a multiplicity ofsequentially serially arranged heated rod-forming stages in each ofwhich the rod has a cross-sectional area slightly greater than it has inthe immediately preceding stage; and cooling the rod in the last stage.

3. The process of claim 2 characterized by that the rod is heated in atleast three of said stages.

4. The method of continuously extruding a mixture of granulated cork andthermosetting binder in the form of a rod comprising the steps of:sequentially forming slugs of the mixture each having the same volumeand the same cross-sectional area; forming a rod therefrom by pressuremoving the slugs one after another into and through an extrusion tube;heating the rod being formed for a substantial portion of its length toset the binder; allowing the rod to radially expand in a plurality ofsuccessive regions lengthwise of the tube; and cooling the last portionof the rod about to discharge from the tube.

5. The method of continuously extruding a mixture of granulated cork andthermosetting binder in the form of a rod comprising the steps of:pressure feeding the mixture to and through a rod-forming extrusiontube; heating the rod being formed for a major portion of its length inthe tube to set the binder; allowing the rod radially to expand incross-sectional dimension in successive regions of the length beingheated, progressively larger for each succeeding region in the directionof travel; and cooling the portion of the rod about to discharge fromthe tube.

6. The process of claim 5 characterized by that the desired density ofthe rod leaving the tube is obtained by controlling the amount ofexpansion in the said regions.

7. The process of claim 6 characterized by that de-. sired density ofthe rod leaving the tube is obtained by controlling the amount ofexpansion in the said regions and by controlling the length of saidregions.

8. In a method of extruding a rod formed from a mixture of granulatedcork and a thermosetting binder, the steps comprising: filling a flaskwith said mixture through an end thereof at a filling station to form acharging slug, transferring said flask to a discharge station at whichsaid slug is aligned with the end of a die tube and with a packingplunger, reciprocating said plunger through said flask and well intosaid tube to compress said slug against a previously deposited slug in aposition far enough from said end to insure against rebound of said sluginto said flask, repeating said operations to provide a flow of saidmixture through said tube, and heating said tube to set said binder, andcharacterized by the application of heat to a pluralityof zones alongthe length of said tube, and by the radial expansion of said mixture insaid zones.

References Cited in the file of this patent UNITED STATES PATENTS1,453,617 Bond May 1, 1923 1,711,962 Nagy May '7, 1929 2,307,055 Mengeret a1. Ian. 5, 1943 2,477,258 MacMillin July 26 .1949 2,560,491 Smith etal. July 10, 1951 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTIONPatent No. 2,830,326

Andrew Weisenburg April 15, 1958 It is hereby certified that errorappearsv in the printed specification oi the abovenumbered patentrequiring correction end that the said Letters Patent should read ascorrected belo Column 6, line 36, for the claim reference numeral "'6"read-,- 5

Signed and sealed this 27th day oi May 1958.

(SEAL) Attest: KARL 3;, AEINE Attesting Officer ROBERT C. WATSONComissioner of Patents

